Thermometer



(Model.)

J. G. SMITH.

THERMOMETER..

' VPamelfnzefirJuly 31,1883..

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.PATENT IIFICEGu JOSEPH GRANDISON SMITH, or QUINGY, ILLINOIS.

THERMOMETER.

SPECIFICATION forming part of Letters Patent No, 282,390, `dated July31, 1883.

Application lcd January i6, 1883. (Model.)

10 au `whom, it may concern:

Beit known that I, J. GRANDISON SMITH, of

` Quincy, in the county of Adams and State of Illinois, have inventedcertain new and useful Improvements in Thermometers 5 and I do herebydeclare the following to be a full, clear,

vand exact description of the invention, such as will enable othersskilled in the art to which it pertains to make and use it, referencebeing had to the accompanying drawings, which form part of thisspecification.

My inventionrelates to an improvement in thermometers which are intendedespecially for use in the house; and it consists, first, in adiamond-shaped case, so that the hand or pointer will be given a largearea or space through which to sweep; second, in the combination of asteel and a brass rod, which are united together and secured at one endto the back of the frame, and which have attached to their free ends asuitable curved or bent wire for operating the pointer by the expansionor contraction of the rods; third, in the peculiar construction of thepointer, whereby it is adapted to be operated by the expansion andcontraction of the compound rod, all of which will be morefullydescribed hereinafter.

The object of my Ainvention is to construct a thermometer in which thepointer moves back and forth over a dial on which the numbers are markedin large igures, and thus indicate at a glance, even from a considerabledistance, exactly what the temperature of the room is.

Figure l is aplan view of my invention complete. Fig. 2 is alongitudinal sectionof the same, taken to one side of the center.

A represents a metallic diamond-shaped case, which is provided withsuitable feet, B,

`to hold it 'above the support upon which it is placed, and to keep theframe out of contact with the vwall when it is hung up, and which willbe provided with a suitable ear, so that it can be hung up against thewall. Through the side of this frame will be made suitable holes orperforations, so that the changes in the temperature will affect thehand more quickly. This case is made diamond-shaped, so that when thehand or pointer is pivoted at one corner its longest end will have thegreatest l possible space through which to sweep, and at the same timeallow a considerable length to be given to the compound `rod by which itis operated. Vere the ease made square, the compound rod could not bemade long enough, and hence it would `not be as accurate where `thechanges are but slight. The bottom of the frame is made of sheet metal,and which has its edges turned up for supporting the glass D. A suitablemetallic iframe, c, of any desired ornamental design, is slipped overthe edges of the frame and made to catch over the top ofthe glass, so asto hold it 4in place. Solder-ed to the frame in one corner are the tworods D F, one of which is made of brass and the other of iron or steel,and these two practically one. These two rods have different degrees ofexpansion, and are soldered together, so one will act as a check uponthe other. Soldered to the end of' this compound rod is the smallL-shaped rod or wire G, which catches between the forked or U -shapedpiece of wire H, that is connected to the pointer. .Soldered to thebottom of the frame is the pivotal rod or standard I, upon which thepointer is placed. This pointer consists of the long Iinger which sweepsover the dial, and the crescent-shaped enlargement whichforms itsshorter end. Either secured to the one side of its shorter end ordoubled back upon itself is the strip J, which is bent as shown, and

ing from its own weight down upon the bottom of the case. Thecounter-weight on the attached to the index-hand to press against thehook of the L-shaped wire attached to the free end of the double bar,thereby causin g the index-hand to rise and fall with the correspondingmotion of the double bar without any play or lost motion between theparts. As the rods are supported together, so as to form index causesone prong of the U-shaped wire4 which forms the lower pivot upon whichthe to bear up againstthe under sideY of the compound rod, and thusprevent the rod from'sink- IOC) pivotal standard passes through both thestrip which is secured to the under side of the pointer and up throughthe pointer itself, the pointer is free to turn in either direction uponits standard, so as to sweep back and forth over the dial. As thecompound rod is' caused to expand by the heat as it lengthens out, theL-shaped pieee attachedto its end bears against one of the U -shapedWires or prongs, which is attached to the pointer at its rear end, andthus sends the pointer around toward the high figures of the scale. Asthis rod contracts, the L-shaped lpiece upon its end 'strikes againstthe other one of the U -shaped wires and causes the pointer to movetoward the lower figures of the scale.

By means of the construction above described a very tasty and ornamentaltherinolneter is produced, which is especially adapted for use inparlors and hot-houses, and

- in which the range of the pointer can be seen It is also spefrom aconsiderable distance. cially adapted as an advertising mediunr7 forupon its large face can be placed advertisements of all kinds.

Having thus described my invention, I

l claimscribed.

3. A pointer in a thermometer, Weighted upon its shorter end, incombination with the U -sllaped Wires which are secured to the under`side of the pointer, the strip which forms the lower bearing for thepointer, and the compound rod provided with an L-shaped connection forcatching between the U -shaped wires, substantially as' described.

In testimony whereof I affix my signature in presence of two Witnesses.

JOSEPH GRANDISON SMITH.

Vtnesses GHARLns SMITH, RICHARD JANsnN, Jr.

